Traditional route control techniques rely upon a single device to manage inbound and outbound routing. The device is typically located at the network edge for the source or the destination. Although there are some route control techniques that use devices operating at each end, the devices operate independently. Since the devices do not coordinate their path selection, the devices may not select the best paths. Thus, there is a need for a route control technique that provides coordinated end to end route control.
Traditional route control techniques are also session dependent, i.e. the same network path is used for the lifetime of the session. One disadvantage of session dependent techniques is that path changes can only be made at the start of a new session. Changes cannot be made within the session. Although this may be acceptable for some applications, there are many applications, such as VoIP and video sessions, where this is not acceptable. Thus, there is a need to provide route control that can make path changes within a session.
Route control requires some degree of network diversity, which has been traditionally achieved through multi-homing. A location is multi-homed if there are multiple network service providers that serve the location. However, it is not always practical for every location to be multi-homed since multi-homing can be expensive and labor intensive. For example, remote branch offices may be single-homed and yet still need to run mission critical operations across a network. Traditional route control techniques are not applicable to single-homed locations. Thus, there is a need to provide route control that can provide network diversity when one of the endpoints is single-homed.